ABSTRACT
A Rotating Biological Contractor (RBC) uses a biological slime of microoganisms that grow on thin disks made of plastic mounted side by side on a shaft.
The shaft mounted disks are rotated slowly so that they are alternately submerged in the incoming wastewater then exposed to air. (The speed can be adjusted.)
The microbes in the wastewater begin to stick to the disk surfaces and grow there until all the disks are covered with a thin layer of biological slime. The microbes get oxygen from the air as the disks are rotated.
The excess growth breaks off from the disks and flows out to a secondary clarifier where it is separated from the wastewater by sedimentation.
The attached growth is similar to that of the trickling filter except here the microbes are rotated into the wastewater rather than the wastewater being distributed over the microbes.
